1. Field of the Invention
The present invention relates to a wall panelling for altering the acoustic properties of a wall, comprising wall elements adapted to have their orientation altered with respect to a wall.
2. Description of the Prior Art
Wall panellings adapted to have their acoustic properties altered are used for altering the acoustic conditions in enclosures employed for different purposes. If for instance the acoustic properties of a room are to be adapted to optimum speech intelligibility, the desired properties include short reverberation and pronounced absorption. Adaptation of the acoustics of a room to musical performances on the other hand requires properties including long reverberation and an increased volume of lateral reflection. In the case of multi-purpose rooms, recording studios and the like, the demands as to acoustic properties may vary within a wide range. Rooms of this type are therefore suitably equipped with wall and/or ceiling elements having variable acoustic properties. These elements may be mounted in such a manner that they can be shifted, rotated or the like to different positions to present surfaces having different acoustic properties facing into the respective room. The wall and/or ceiling elements thus employed, referred to in the following as "wall elements" for brevity, are preferably of a type having reflecting and absorbing surfaces adapted to be selectively brought to an operative position.
Structural elements hitherto preferably employed for the purpose outlined above were of a three-dimensional type in the form for instance of cylindrical or triangular columns mounted for rotation about a fixed axis. A panelling of this type suffers from the serious disadvantage that its installation requires a considerable depth of about 50 cm or even more, and that the maneuverability and adjustability of the wall elements is impaired by their considerable volume. As a whole, the hitherto known wall panellings of this type lead to a twofold cost increase in that the enclosed volume of a room has to be increased for achieving a predetermined open room volume, and in that the manufacturing costs for such bulky, heavy wall elements and their rotatable mounting are quite onerous.